Any old shotgun stamped "44 Cal." or using the number 44 is chambered for the cartridge which eventually was modified into today's .410 gauge bore. They reportedly fire the .410 ok, but are not as good generally as the true .410 shotgun.
Yes
Not a thing
There is no 44 gauge gun.
Yes. The Mossberg 500A1 is a .12 gauge shotgun.
.61 Caliber is the same as 20 gauge. Rifles are generally measured in caliber which is expressed as bore diameter. A .44 magnum means a .44 inch bore; similarly countries with the metric system use metric bore measurements (ie. 9mm Luger) Shotgun measurements are expressed in gauges. Gauge measurements are fractions of a 1 pound ball of lead. A one gauge shotgun shoots a one pound ball of lead. A 12 gauge takes 12 round lead balls to equal a pound and a 10 gauge equals a tenth of a pound. The smaller the gauge; the larger the bore. The only shotgun I am aware of that is measured differently is the .410 shotgun which is approximately .45 caliber or a 67.62 gauge.
To determine exact value of a 1904 Marlin 12 gauge pump shotgun, you would actually have to take a number of factors into consideration. The main thing to consider would be the condition of the shotgun.
THE GUN IS A .44 CALIBER SHOTGUN, NOT A .410 CALIBER. I HAVE BEEN TOLD THAT IT MAY HANDLE VERY SHORT .410 CALIBER SHOT SHELLS OF LOW POWER BUT, IT COULD RISKY.
Yes, a 12 gauge shotgun is considered a firearm.
A bolt action shotgun in 12 gauge.
There is no such shotgun gauge.
What is the value oof a .410 gauge shotgun
Standard 16 gauge shotgun shells.